Question

Post-Lab Report (Use the In-lab observations to complete the laboratory report. Turn in to your Instructor when you have completed the report.) PART A. KIO, SOLUTION (SOLUTION A). Molarity of KIO, stock solution - 02_M Total volume of reaction 100 m l Initial conc. Time Mixture mL used [KIO (M) 1/ [KIO 1 required 10.0 ml,002 M 50 294 S ml 1004 M 250 1285 mt ooM I lolos 87 Show your work for the calculation for the initial concentration of [KIO Toomix 0.002M-max 100mc in Mixture 1. m Top MLX.02 m- 1002m. mas TOOME POST-LAB You will use graphical analysis to determine the order of [KIO) in this reaction. When you determine the order, you will also calculate the specific rate constant, k, relative to [KIO, To do this you will plot the three different treatments of the concentration versus time. In the space provided beside each graph you will state whether that graph established the order of the reaction for KIO, and if it does, calculate the specific rate constant k using your data from that plot

I am not sure if the graph on number 1 would be a 0 order reaction. Also on number 3 I am not sure how to do the rate law and find k

Answer 1

In graph number 1, the concentration vs time plot is not a straight line parallel to the x-axis. If the reaction to be zero-order, the graph appears to be a line parallel to the x-axis.

In graph number 3, the plot confirms that the reaction is second order. Now, for a second-order reaction, we can write it as

d[KIO₃]/dt = -k[KIO₃]²

The above expression can be now integrated to give the required rate law as

1/[KIO₃] = 1/[KIO₃]_o + kt

Once we know the rate law, we can substitute the values i.e. concentration of KIO₃ at time t=0 sec which is [KIO₃]_o, the concentration of KIO₃ at time t thus leaving the only unknown in the equation as k. We can then solve for k.